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%I #4 Mar 30 2012 18:50:25
%S 9,27,4,8,9,0,8,9,25,2197,27,16,49,0,16,25,25,27,27,36,25,49,27,25,
%T 125,27,36,32,225,6889,32,36,49,0,36,100,64,1369,64,49,49,0,484,125,
%U 49,289,128,49,81,0,100,196,729,81,64,64,121,0,900,64,125,0,64,100,81,0,1156
%N Least perfect power b^e such that b^e-n is also a perfect power, or 0 if no such perfect power exists.
%C a(A074981) = 0.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PerfectPower.html">Perfect Power</a>.
%e a(30) = 6889: 30 = 83^2 - 19^3.
%Y Cf. A001597.
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Oct 10 2002